Liquid crystal displays are a kind of flat and ultra-thin display devices with advantages such as small volume, small thickness, light weight, small energy dissipation and low radiation and are widely applied in various electronic display devices. The display effect of a liquid crystal display is mainly determined by the liquid crystal display panel that mainly comprises an array substrate, a color filter substrate and a liquid crystal molecule layer between the two substrates. The array substrate determines the response time and the display effect of the liquid crystal display panel to a large extent.
On the array substrate are generally included structures such as thin film transistors and pixel electrodes; and a thin film transistor specifically comprises structures such as a gate electrode, an active layer, a source electrode and a drain electrode. In the manufacturing process of the array substrate for a bottom-gate type thin film transistor, typically five patterning processes are required to form gate electrodes, active layers, source electrodes and drain electrodes, drain electrode via holes, and pixel electrodes respectively. Manufacturing of the array substrate for a top-gate type thin film transistor requires more complex patterning process to form various layer structures.